Understanding Task Design Trade-offs in Crowdsourced Paraphrase Collection

Linguistically diverse datasets are critical for training and evaluating robust machine learning systems, but data collection is a costly process that often requires experts. Crowdsourcing the process of paraphrase generation is an effective means of expanding natural language datasets, but there has been limited analysis of the trade-offs that arise when designing tasks. In this paper, we present the first systematic study of the key factors in crowdsourcing paraphrase collection. We consider variations in instructions, incentives, data domains, and workflows. We manually analyzed paraphrases for correctness, grammaticality, and linguistic diversity. Our observations provide new insight into the trade-offs between accuracy and diversity in crowd responses that arise as a result of task design, providing guidance for future paraphrase generation procedures.Comment: Published at ACL 201

Nanosci. Nanotechnol. Lett.

Carbon nanotube (CNT) forests were synthesized at various temperatures between 805-830 degrees C by water-assisted chemical vapor deposition (CVD). The height and the yield of CNT forests increased about 3 times as the temperature rose, while the crystallinity improved slightly, which suggests that relatively high growth temperature was desirable for efficient growth of high-quality CNTs. Investigation on growth curves revealed that the CNTs grew faster as the temperature increased, but the catalyst lifetime first showed a notable increase, then a decrease. Effects of the temperature on the growth kinetics were interpreted in terms of heat history of carbon feedstock and evolution of the catalyst morphology.Carbon nanotube (CNT) forests were synthesized at various temperatures between 805-830 degrees C by water-assisted chemical vapor deposition (CVD). The height and the yield of CNT forests increased about 3 times as the temperature rose, while the crystallinity improved slightly, which suggests that relatively high growth temperature was desirable for efficient growth of high-quality CNTs. Investigation on growth curves revealed that the CNTs grew faster as the temperature increased, but the catalyst lifetime first showed a notable increase, then a decrease. Effects of the temperature on the growth kinetics were interpreted in terms of heat history of carbon feedstock and evolution of the catalyst morphology

Brain relaxation using desflurane anesthesia and total intravenous anesthesia in patients undergoing craniotomy for supratentorial tumors: a randomized controlled study

Abstract Background Satisfactory brain relaxation is essential in neurosurgery. Desflurane anesthesia and propofol-based total intravenous anesthesia (TIVA) have different effects on cerebral hemodynamics, potentially contributing to discrepant brain relaxation. The purpose of this study was to compare the effects of desflurane and TIVA on brain relaxation in patients undergoing craniotomy for supratentorial tumors. Methods In this randomized, controlled study, we enrolled patients aged 18–60 years, with ASA I–III, who were scheduled to undergo elective craniotomy for supratentorial tumors. Patients were randomly assigned in a 1:1 ratio to receive desflurane anesthesia or TIVA. The primary outcome was the proportion of satisfactory brain relaxation. Secondary outcomes included emergence and extubation times, recovery of cognitive function and postoperative complications. Results Of 369 patients who were assessed for eligibility, 111 were randomized and 110 were included in the modified intention-to-treat analysis (55 in the desflurane group and 55 in the TIVA group). The proportion of satisfactory brain relaxation was similar between the two groups: 69% in the desflurane group and 73% in the TIVA group (RR: 0.950, 95% CI: 0.748–1.207; P = 0.675). Patients assigned to the desflurane group had shorter emergence (10 [8–13] min vs. 13 [10–20] min, P < 0.001) and extubation times (13 [10–18] min vs. 17 [13–23] min, P < 0.001), and better recovery of cognitive function at 15 min after extubation (16 [0–24] vs. 0 [0–20], P = 0.003), but experienced increased postoperative nausea and vomiting (PONV) (16 [29%] vs. 6 [11%] P = 0.017) and tachycardia (22 [40%] vs. 9 [16%], P = 0.006) during recovery. Conclusions Desflurane anesthesia and TIVA provide similar brain relaxation in patients without intracranial hypertension undergoing elective craniotomy. Desflurane accelerates the recovery from anesthesia but is associated with increased PONV and tachycardia during the recovery period. Trial registration Clinicaltrial.gov (NCT04691128). Date of registration: December 31, 2020

Atomic ruthenium-riveted metal-organic framework with tunable d-band modulates oxygen redox for lithium-oxygen batteries

Non-aqueous Li-O2 batteries have aroused considerable attention because of their ultrahigh theoretical energy density, but they are severely hindered by slow cathode reaction kinetics and large overvoltages, which are closely associated with the discharge product of Li2O2. Herein, hexagonal conductive metal-organic framework nanowire arrays of nickel-hexaiminotriphenylene (Ni-HTP) with quadrilateral Ni-N4 units are synthesized to incorporate Ru atoms into its skeleton for NiRu-HTP. The atomically dispersed Ru-N4 sites manifest strong adsorption for the LiO2 intermediate owing to its tunable d-band center, leading to its high local concentration around NiRu-HTP. This favors the formation of film-like Li2O2 on NiRu-HTP with promoted electron transfer and ion diffusion across the cathode-electrolyte interface, facilitating its reversible decomposition during charge. These allow the Li-O2 battery with NiRu-HTP to deliver a remarkably reduced charge/discharge polarization of 0.76 V and excellent cyclability. This work will enrich the design philosophy of electrocatalysts for regulation of kinetic behaviors of oxygen redox.This work was supported by National Natural Science Foundation of China (52171215), the Tianjin Natural Science Foundation (19JCJQJC62400), and Haihe Laboratory of Sustainable Chemical Transformations

High-Efficiency Lithium-Ion Transport in a Porous Coordination Chain-Based Hydrogen-Bonded Framework

Fast and selective Li+ transport in solid plays a key role for the development of high-performance solid-state electrolytes (SSEs) of lithium metal batteries. Porous compounds with tunable Li+ transport pathways are promising SSEs, but the comprehensive performances in terms of Li+ transport kinetics, electrochemical stability window, and interfacial compatibility are difficult to be achieved simultaneously. Herein, we report a porous coordination chain-based hydrogen-bonded framework (NKU-1000) containing arrayed electronegative sites for Li+ transport, exhibiting a superior Li+ conductivity of 1.13 × 10–3 S cm–1, a high Li+ transfer number of 0.87, and a wide electrochemical window of 5.0 V. The assembled solid-state battery with NKU-1000-based SSE shows a high discharge capacity with 94.4% retention after 500 cycles and can work over a wide temperature range without formation of lithium dendrites, which derives from the linear hopping sites that promote a uniformly high-rate Li+ flux and the flexible structure that can buffer the structural variation during Li+ transport